Vat dyestuffs of the anthraquinone series and process of making same.



cylic acid are introduced at 0 G. into 100 UNITED STATES PATENT OFFICE.

MAX HESSENLAND, or HocHsr-oN-THE-MAIN. GERMANY, ASSIGNOR To FARBWERKE vomvr. MEISTER LUCIUS & BRUNING, or HTO'CHST-ON-THE-MAIN, GERMANY, A coa- PORATION 0F GERMANY.

VAT DYES'IUFFS OF THE ANTHRAQUINONE SERIES AND PROCESS OF MAKING SAME.

No Drawing.

To all whom it may concern:

Be it known that I, MAX HESSENLAND, Ph. D., chemist, a-citizen of the Empire of Germany, residing at Hochst-on-the-Main, Germany, have invented certain new and useful Improvements in Vat Dyestuifs of the Anthraquinone Series and Processes of Male By replacing the hydrogen of the amino group by radicals, such as benzoyl, phenyl, naphthyl, ant-hraquinonyl, the properties of the dyestuffs can be varied.

In carrying out my invention, I may, for instance, proceed as follows: 8 parts by weight of 4-aminoanthraquinonyl-l-thiosaliparts of chlorosulfonic acid and the mixture is stirred for one hour at the said temperature. The mass is then gradually heated to -520 C. and the stirring continued until theformation of the thioxanthone is comqileted, which occurs after about 68 hours. The dyestuflf is separated by pouring the mass'irto ice-water; it forms a blue powder, insoluble in water, alcohol and ether, soluble in hot nitrobenzene with a blue color,

dissolving in alkaline hydrosulfite with red- Speciflcation of Letters Patent.

Application'flled March 1, 1911. Serial No. 611,577.

Patented Oct. 31, 1911.

dish-blue color and dyeing cotton in the vat and by subsequent exposure to the air beautiful .blue tints of excellent fastness.

Having now described my invention, what I claim is:

1. The process ,of producing vat dyestuffs containing sulfur, which consists in treating 4-amino-anthraquinonyl-l-thiosalicylic acid with dehydrating agents.

2. As new products, the dyestuffs containing sulfur, which are l-aminoanthraquinone- -l-thioxanthones of the constitution:

in which R stands for a benzene residue, being blue powders insoluble in water, alcohol and ether, soluble in alkaline hydrosulfite with a reddish-blue color and dyeing cotton fast blue tints.

3. As a new product, the 4-aminoanthra.

quinone-l-thioxanthone of the constitution:

7 MAX HESSENLAND.

Witnesses JEAN GRUND, CARL GRUND. 

